UBC355XLT

[shipspotter]

Hi,

I am having issues with reception on my UBC 355XLT.I listen to the marine band and never had any issues until today with reception breaking up and very poor I live about 10 kms from the ports. I use an outdoor antenna rubber ducky type . Sometimes the reception is loud and clear 5 by 5 and next minute its breaking up and down to 1 by 5 and all on the same feq. Anyone have any suggestions what I could do.

Thanks

[comport1]

Hi and welcome to the forum...

This sounds normal for marine band, or any simplex transmissions for that matter, So, a few things here to consider. If you are listening to the marine band, especially near a port, you are most likely receiving "simplex" transmissions, so, you say one minute it's 5 by 5 then down to 1 by 5. So, the 5 by 5 station could be a ship, or port tower or a shipping agent or company in an office building, transmitting on higher power (25 watts). The next "over" could be a port worker using a handheld VHF marine radio, and could be using 1 watt of power. Cold also be the first stations I mentioned as well, using low power (1 watt). You'll find most ship/port operations using simplex on Marine Band, and VMR's and Coastguards usuing Repeters. So if your 10k away from the port, and line of sight, you are probably hearing the weak stations as well.

Also another thing, check all your connections and cables for any problems, like, loose connectors or water in coax etc.

Hope this helps

Cheers

[shipspotter]

Thank you for the advice, I am going to run new cable all one length so no connectors unlike what I have at the moment with connecters and raise the antenna higher. As for Simplex transmissions does that mean no repeater.

[tanger32au]

As for Simplex transmissions does that mean no repeater.

It sure does, so the signal will change strength as the ships move around.

[shipspotter]

As for Simplex transmissions does that mean no repeater.

It sure does, so the signal will change strength as the ships move around.

Ok thanks for that, Cheers

[shipspotter]

Hi, I have ran brand new cable and raised the antenna about 2 meters higher, but the problem still exists the port only 10 kms away the transmissions are still 1 by 5 I can still hear the ships loud and clear but the port control is 1 by 5, yet I can now hear port of Geelong 5 by 5 which is over 100 km away. Up till now listening to the port it was loud and clear, maybe something to do with the weather ??

[shipspotter]

Hi, past few days I have had no problems with receiving transmissions all 5 by 5 the weather has been overcast, but today the weather is sunny not a cloud in the sky and no wind and I cant receive any transmissions. Any clues

[X-Firey]

I think you may have answered your own question. Radio communications can be affected by many things and one of the main ones is atmospheric conditions/weather. I don't think there is anything wrong with what you are doing as you have stated you are now receiving the port of Geelong. Also others have mentioned the difference in transmission power and the fact that most marine transmissions are simplex.

[shipspotter]

I think you may have answered your own question. Radio communications can be affected by many things and one of the main ones is atmospheric conditions/weather. I don't think there is anything wrong with what you are doing as you have stated you are now receiving the port of Geelong. Also others have mentioned the difference in transmission power and the fact that most marine transmissions are simplex.

Ok thanks X- firey I'm going go to my local two way radio shop and have a chat to them, thanks everyone for the help .Cheers

[shipspotter]

Just an update at what i have done still no improvement, i have visited a couple of two way radio stores and there advice was to lower the antenna which i have done still the same. The only thing i can think of now is a palm tree next door which about 5 meters away from the antenna and the antenna is just above it maybe this could be the issue .

[X-Firey]

I guess you could try relocating the antenna to see if reception improves and while you are at it double check your connections. As a matter of interest what type of antenna are you using, is it a broadband antenna or a marine band antenna?

[shipspotter]

Its a broadband antenna, jack of all trades master of none. I am going to buy a vhf antenna which is tuned to 133-174 band and run 50 ohm coaxial which I hope will solve the problem. I moved the antenna further away from the tree as far as the cable length would allow but it was no better.

Cheers and thanks for the advice.

[X-Firey]

Before you spend the dollars on an antenna you could try making a 1/4 wave ground plane antenna.
1/4 ground plane antennas are cheap and easy to make and you could cut it to suit your specific requirement (156 mHz). There a plenty of plans for these antennas and antenna cutting charts on the internet.
Anyway just a thought and I hope you find something that works well for you.
The joys of the hobby...

[dags19]

could be somebodys building a building etc in line of sight stuffing your reception up,yep experiment moving the aerial around first

[shipspotter]

I am using the wrong type of coaxial really as well i got RG59U so that wouldn't be helping as well so i will replace that with RG58.As for making my own antenna i don't have anything to make it out of , I am going to get a RFI end fed diploe antenna and tune that to 156 mhz.

There is no buildings being built nearby the nearest about 4-5 kms away.


Thanks guys again for the help.

[Yipyip46]

Good morning All, I have been following this thread for a while. Early on you said that you hear the ships and the Geelong port 5 x 5. This would indicate that the receiver and antenna are working. The problem as I understand it is that the close by port signal has dropped.

I would be going for a trip to see if the port tower is under maintenance or had new antennas installed. Maybe a telco has added an extension to their antenna system that is now interfering with the signal path. If there is a tower or a high building they love to over crowd the top of it with their systems.

Also try going portable with the scanner.Check out sites the same distance from the port tower to the left and right of your location.

Maybe there was a reported interference problem involving the port frequency and they have dropped to low power while it is sorted. There is a whole range of reasons why signals drop.

Do some logical deductions like have other frequencies you listen to changed? If not then your receiver and antenna are likely ok. Don't jump to the conclusion that the fault is at your end, stop, think about what is happening and test the simple things first. I hope this helps narrow down your problem.

Regards Yipyip

[Vkfour]

The coaxial cable you are using won't make a whole lot of difference for receiving, in fact, you won't notice any difference. You can make antennas out of almost anything, especially if it is an antenna to see what is going to happen. A dipole only needs two pieces of wire and a few pieces of plastic. I've seen them use pressure pack lids! End fed dipole?

[shipspotter]

Thanks Yipyip and Vkfour for the help.